1. Field of the Invention
This invention relates to a data processing system for handling the output from a computer so as to record the corresponding data on a microfilm device in a computer output microfilmer (COM).
2. Description of the Prior Art
A computer output microfilmer (hereinafter referred to as COM) is used as an output unit of a computer in the same manner that a line printer would be used. Generally, the COM is superior to other output units in that it is suitable for recording data at a high speed. Hence, it is desirable to make the best use of the merit of the COM or to further increase the recording speed thereof.
The COM is generally associated with a computer output read-out unit having a storage unit such as a magnetic recording tape, and a central processor unit (CPU) having a buffer storage. The COM (or recording unit) also has a buffer storage associated with it.
In a conventional data processing system used in conjunction with the COM, data stored in the storage unit are read out on a page by page basis from the computer output read-out unit, and are written directly into the buffer storage of the CPU. The data of one page are processed by the CPU and the processed data of the one page are transferred to the buffer storage of the recording unit to be stored therein. The recording unit (COM) reads out the data stored in the buffer storage thereof, and records the data on a microfilm by means of a laser beam scanning recorder, or an optical recording system using a cathode ray tube (CRT).
In the conventional system, the data is read out from the storage unit under the control of the CPU. Accordingly, the CPU is occupied in controlling the storage unit while the data is being read out, and reading data of one page and processing data of another page cannot be conducted in parallel. This increases the throughput time of the COM.